Bag closure



Jan. 30, 1951 W. O. STRELLER BAG CLOSURE Filed April 14, 1948 INVEN TOR.WOLFGANG O. TRELLER.

Mmm/EVS.

Patented Jan. 30, 1951 UNITED PATENT (JFICE BAGA CLOSURE wolfgang, NewYork, rN. Y., assignory to St. Regis k laper Company, New York, N. Y., acorporation of New York ppiieto Apri-1 1'4, 1948;sria1N'. 21,059

. 2 claims. (c1. 229-62) This' invention pertains' tol improvements invand closures for paper bags;Y and the like, and

more especially to bag end closures of the sewn seam type. y

A common form of end closure for relatively large bags, i. e., thoseadapted' to packaging goods in bulk, such, for example; as cereals,flour,v ce* ment, etc., is' one wherein` the oppostely disposed will'portions of the bag end are overlappedy with a separate sealing tape ofheavy paper or the like,

and secured together bymeans of a seam, which may' comprise anseries ofstaples, but more preferablly comprises a continuous sewn' seam ofcotton thread or cord, or otherl suitable organic material. A seriousobjection to this' type of end closure resides in'l the fact that theneedle holes resultingfro'rn'the sewing operation permit thepackagedog'oods, especially if of finely ground o'r pulverulentmaterial, to sift'l out, and' these holes further` provide points ofingress for insects and the like',v particularly as applied to'packagedcoingv estibles ,y such as flour, cereals, etc. Likewise,`these'lnet-dle holes permit the bag contents to beA easily penetrated bymoisture,` molds, fungi; etc., from theV outer atmosphere', and alsoprevent the packaging therein of goods of a viscous or easily owablecharacter. n

Many attempts have heretofore been made to overcome this' difliculty, asfor example, superimposing on the sealing tape, on one or both sidesthereof, and along the line of stitching, suchstitching-perforation-filling materials asv lter cord, paper strips orthe like; or by attempting to accomplish the same result by folding theseal-V ing tape along the stitching` line' inonefor more folds. All suchexpediente are objectionable, however, either by reason of theadditional e'xv pense of fabrication thereby entailed, or due to thefact that such expedients are either ineffective or weaken the' bag endclosure.

In accordancev with the present invention, it is proposed to overcomethese objections to prior constructions in ano-extremely simple, yeteffective, manner. Thus, in accordance with the in-v vention` herein,the sealing tape, which overlaps the bag end,` is foldedback upon itselfalong 'an intermediateportion thereof; on; one or both' sigles of thebag, to fornr a pleat or' pleats substantially paralleling the bag end,and the closure completed by means of stapling, or more preferably, bymeans of a sewn seam passing through the pleated portion or portions ofthe tape and the bag walls interposed therebetween. In conjunctiontherewith, the extremities of the sealing tape are adhesively bonded tothe opposite side walls, respectively, of the bag.

By virtue of this construction, the folded-'over or pleatedr portions ofthe sealing' tape effectively ll the stitching perforations, while theadhesive bonding ofv the sealing tape extremities to the opposite bagwalls, respectively,` not only increases the rupture or breakagestrength of the bagv end when packed with the packaged goods; inhandling or throwing about, etc., but inv addition; seals off exposureof the stitching perforations,` whichY would otherwise occur between thebag walls and the edges of the sealing tape.

The invention is, of course, applicable'V to end closures for alltypesrof bags, and is especially effective as applied to multiwall ormulti-ply bags such as are employed inthe industry in treinen-` dousquantities for the packaging of goods in bulk as aforesaid.

In the drawings v Figure l is a" plan view of the upper end of a valvetype of m'ultiwall bag, illustrating an en d closure `in accordance withone modification of the invention, Figure 2Y being a sectional viewthereof, taken at 2--2 of Figure 1. Figure?, is a sectional view,similar to Figure 2, illustrating a" furtherrmodication of theinvention. v

o Figure 4 is a plan view, similar to Figure 1,- sh'o-wing a.k furthermodication of the invention, appliedV as an end closure of an initiallyopenended type Vofbagor asan end closure at the lower end of either uavalve type or open-ended type of bag. Figure 5 is a sectional view ofthe Figure 4 modication, taken at 5--'5 of Figure 4; while Figure 6 is asectional view similar to Figure 5, but illustrating a furthermodification thereof. l y

Referring to Figures l and 2,` there is shown generally at Iii, theupper end v of a multiwall bag comprising a number of bag plies asindicatedat I I, this bagl being of the valve type, i. e., provided withya valve sleeve corner as indicated at l2, to provide an aperture asindicated at I 3, for purposes of filling the bag with the goods to bepack# aged therein, for example, flour, cereals, cement or the like.`The bag is gusseted along the lateral edges as indicated at I4, I5, toprovide a flat construction prior to filling. y Vlr accordance with themodification of the inven ...on illustrated in Figures land 2', theupper endsk i6 of the bag plies I I are overlapped with a strip ofsealing tapev Il, composed, in the niodi cation illustrated, of crepedpaper as indicated at I8. The sealing tape il overlaps the ends I6 ofthe bag plies I I to the distance I9, 20 along the opposite, outer sidewalls 2l, 22, respectively, of the bag. An intermediate portion of thesealing tape is folded back on itself, on one side of the bag, in themanner shown at 23 in Figure 2, thereby to provide a pleat substantiallyparalleling the bag end, as illustrated more clearly in Figure 1. Theclosure is completed by means of a seam 24, which may be a series ofstaples, but more preferably comprises a sewn seam, which passes through`the opposite sides of the sealing tape, including the pleated portionthereof, and through the interposed bag plies in the manner clearlyillustrated in Figure 2.

A common type of stitch which may be employed for the seam 24, where asewn seam is employed, is known as the double chain stitch, in which, onthe rear side of the same, the loops of the needle thread 25, Figure 2,are chained into loops of a looper thread 23. It has been found that thelooper side of the seam is ordinarily strong enough, and lls the needleperforations on the loop of thread on the 26 side Suniciently, that itsuiiices in many instances to omit a pleat in the sealing tape on thelooper side, as shown in Figure 2, and merely to provide the pleat onthe opposite side of the sealing tape, the latter as shown at 23.

A much stronger construction and more eiective closing of the needleperforations is, however, obtained in accordance With the modificationof the invention illustrated in Figure 3, wherein the sealing tape isfolded back on itself on both sides of the bag to provide oppositeiydisposed, pleated portions 23 and 21, throug which the seam is sewn asat 24.

It will be observed in both the Figures 2 and 3 modifications, that thelower extremities i9 and 2li of the sealing tape extend well below thepleated portions 23, 24 thereof, to provide sealing tape portions 28 and29, disposed below the pleats, which portions are rmly bonded orcemented to the outer surfaces of the outer bag plies 2|, 22, thereby toincrease the strength of the closure in handling or throwing about ofthe bag when packed, and also to seal the lower extremities i9 and 20 ofthe sealing tape to the bag walls 2|, 22 against exposure of thestitching perfcrations which might otherwise occur therebetween in theabsence of such bonding of portions 28 and 29 of the sealing tape to theopposite bag walls 2 I, 22.

it will be noted that in the Figures 2 and 3 modifications the sealingtape is pleated in such fashion that the pleats point downwardly, i. ctoward the median line of the bag. In the Figures 4 6 inc.modifications, the pleating is in the opposite direction, i. e., thepleats point toward the bag end. Thus, referring more particularly toFigures 4 and 5, there is illustrated generally at 30, an end of amultiwall or multi-ply bag, the plies of which are indicated at 3|. Theextremities 32 of the bag plies are overlapped with a strip 33 ofsealing tape composed, as in the previous modiiications, of creped paperas indicated at 34, this sealing tape extending downwardly along theopposite sidewalls 34, 35 of the bag to the distances 3E, 3lrespectively. An intermediate portion of the sealing tape on one side ofthe bag is folded back on itself to form a pleat substantiallyparalleling the bag end as shown at 33, and the bag end closure iscompleted by a stapled or stitched seam 39, passing through the oppositesides 40, 4| of the sealing tape in the pleated portion 38 thereof, andalso through the interposed bag plies 3|, as shown. It will be notedthat in this modification the pleat 38 is so formed in the sealing tapeas to point toward the bag end, i. e., toward the upper extremities 32thereof.

As in the Figure 2 modification, if the .seam 39 comprises a sewn seamof the double chain stitch type, a pleat such as 39 may also berequired, for many applications, only on the side opposite to the looperside 42 of the stitching. As above stated, however, a strongerconstruction is secured, and one in which the stitching perforations aremore effectively closed, if pleats are provided on both sides of thesealing tape as illustrated in Figure 6 at 38 and 43, respectively. Inthe Figure 6 modification, as in Figure 5, both of the pleats 38 and 43are so formed as to point to the bag end 32 as shown. Also, as in theFigures 2 and 3 modifications, the lower extremities 44, 4| of thesealing tape are rmly bonded or cemented to the opposite sidewalls 34,35, respectively, of the bag, being interposed adhesively, and forpurposes above stated. The modifications of Figures 2 and 3 arepreferred to those of Figures 5 and 6, as the former have been found bytests to give a somewhat stronger construction'. I

What I claim is:

1. A bag having oppositely disposed walls terminating in a bag end, anda sift-proof closure therefor comprising a separate sealing tape foldedover astride said bag end, an intermediate portion of said tape beingfolded back upon 1tself on at least one side of said bag, forming apleat substantially paralleling said end, and a seam passing through thebag walls and the op- Y positely disposed portions of said sealing tape,

including the pleated portion thereof, the oppositely disposed edgeportions of said sealing tape extending below said pleat and beingadhesively bonded to the contiguous bag walls, respectively.

2. A bag having oppositely disposed walls terminating in a bag end, anda sift-proof closure therefor comprising a separate sealing tape foldedover astride said bag end, an intermediate portion of said tape beingfolded back upon itselfv REFERENCES CITED The following references areof record in the le of this patent:

UNITED STATES PATENTS Number Name Date 2,140,104 Cheatham Dec. 13, 19382,345,434 Sterling i Mar. 28, 1944 Hartman I -Q Mar. 16, 1.948

